A bruise (layman's term), also called a contusion (medical term), is a type of hematoma of tissue in which capillaries, and sometimes venules, are damaged by trauma, allowing blood to seep, hemorrhage or extravasate into the surrounding interstitial tissues. Trauma sufficient to cause bruising can occur from a wide variety of situations including accidents, falls and surgeries.
In a bruise, distress to tissue causes capillaries to break under the skin, allowing blood to escape and build up. As time progresses, blood seeps into the surrounding tissues, causing the bruise to darken and spread. Nerve endings within the affected tissue detect the increased pressure which, depending upon the severity and location, may be perceived as pain or pressure. The damaged capillary endothelium releases endothelin, a hormone that causes narrowing of the blood vessel to minimize bleeding. As the endothelium is destroyed, the underlying von Willebrand factor is exposed and initiates coagulation, which creates a temporary clot to plug the wound and eventually leads to restoration of normal tissue.
Treatment for light bruises is minimal and may include rest, ice, compression, elevation, painkillers and, later in recovery, light stretching exercises. Immediate application of ice while elevating the bruised area may help reduce swelling. Applying a medicated cream containing mucopolysccharide polysulfuric acid (e.g., Hirudoid) may speed the healing process. Other topical creams containing skin-fortifying ingredients, such as retinol or alpha hydroxy acids, can improve the appearance of bruising faster than if the bruise is left to heal on its own. Anti-inflammatory treatments in the Arnica family have also been used to treat bruises, with questionable efficacy.
A burn is a type of injury to skin caused by heat, electricity, chemicals, friction, lasers, ice or radiation. Burns that affect only the superficial skin are known as superficial or first-degree burns. When damage penetrates into some of the underlying layers, it is a partial-thickness or second-degree burn. In a full-thickness or third-degree burn, the injury extends to all layers of the skin. A fourth-degree burn involves injury to deeper tissues, such as muscle or bone.
The techniques used to treat burns depends upon the severity of the burn. Superficial burns may be managed with little more than simple pain relievers, while major burns may require prolonged treatment in specialized burn centers. Cooling with tap water or ice may help relieve pain and decrease damage. However, prolonged exposure to cold water or ice may also cause dermal injury, such as frost bite, and necrosis. Patients who use ice therapy for chronic pain can develop cold panniculitis or “ice-pack dermatitis” in which erythematous plaques occur. Further, ice is difficult to apply and should only be applied for short periods of time. In the case of extensive burn, the dermal barrier and thermal insulating properties of the skin is compromised and prolonged ice exposure can also lower body temperature to the point of hypothermia. Partial-thickness burns may require cleaning with soap and water, followed by dressings. Full-thickness burns usually require surgical treatments, such as skin grafting. Extensive burns often require large amounts of intravenous fluids because the subsequent inflammatory response will result in significant capillary fluid leakage and edema. The most common complications of burns are related to infection, pain and scaring.
While treatments have been developed to treat bruises and burns, they have varying degrees of effectiveness. In the case of bruises from facial injections and facial surgery, for example, the dark puffiness associated with the bruise can not only be painful, but also very embarrassing. There are anecdotal reports that Arnica taken before surgery can help reduce bruising but has little effect on the bruise once the bruise has occurred. For that reason, more effective treatments are needed to quickly minimize the effects of bruises and burns.